telkom ******** debit order

i was charged R202 for a debit order which was supposed to run on the 25th of august and however ran on the 27th,telkom agents are advising that this a charge for an unpaid debit order which they tried to run on the 24t,which is a day before my agreed payment date,this is unconstitutional and is not on my contract,i want my money back or il reverse the whole amount,id rather rather be blacklisted...my contact number is ********** 021